US5035750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processing method for semiconductor wafers
Assignee: Taiyo Sanso Co Ltd
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Filing: 1990-01-25
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Granted: 1991-07-30
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Expires: 2010-01-25
Abstract
Abstract A cleaning method and a gettering method for semiconductor wafers comprises blasting frozen particles at the surface of a semiconductor wafer. A processing apparatus for a semiconductor wafer comprises means for forming ultrafine frozen particles and means for blasting the frozen particles at the surface of a semiconductor wafer to perform either the gettering or the cleaning of the semiconductor wafer. In one form of the invention, the frozen particles are formed by spraying a mist of water into a chamber partially filled with liquid nitrogen, which freezes the mist to form ice particles. In another form of the invention, the frozen particles are formed by spraying a mist of water into a chamber containing cold nitrogen gas, which freezes the mist to form ice particles. In another form of the invention, the frozen particles are formed by heating water to form water vapor and introducing the water vapor into a freezing chamber containing a two-phase mixture of a coolant which freezes the vapor into ultrafine particles. The frozen particles are blasted at a semiconductor wafer through a blasting nozzle by a gas such as nitrogen gas. When the frozen particles are used for gettering, they may further include nuclei of particles such as silica powder.
Inventors
- 👤 Masuo Tada
- 👤 Takeki Hata
- 👤 Takaaki Fukumoto
- 👤 Toshiaki Ohmori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:13
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; B; B08; B08B; B08B7/00; B08B7/0064; B08B7/0092; B24; B24C; B24C1/00; B24C1/003; B24C3/00; B24C3/32; B24C3/322; F; F25; F25C; F25C1/00; H10P36/00; H10P36/03; Y; Y10; Y10S; Y10S438/00; Y10S438/906
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
36 words
A method of cleaning a semiconductor wafer comprising: blasting ice particles formed from ultrapure water containing carbon dioxide gas and having a specific resistance no more than 1 megohm-cm at a surface of a semiconductor wafer.
Claim 2
Independent Claim
36 words
A method of cleaning a semiconductor wafer comprising: blasting ice particles formed from ultrapure water containing carbon dioxide gas and having a specific resistance no more than 1 megohm-cm at a surface of a semiconductor wafer.
Claim 3
Dependent Claim
31 words
A method as claimed in claim 1, including blasting the ice particles at the surface of said semiconductor at an angle of 30°-80° with respect to the surface of said semiconductor.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 1 wherein the diameters of said ice particles range between 1 μm-100 μm.
Claim 5
Dependent Claim
22 words
A method as claimed in claim 1, including blasting the ice particles at the surface of the semiconductor wafer with a gas.
Claim 6
Dependent Claim
12 words
A method as claimed in claim 4 wherein said gas is nitrogen.
Claim 7
Independent Claim
48 words
A method of cleaning a semiconductor wafer comprising: blasting ice particles at a surface of a semiconductor wafer; heating the semiconductor wafer; and heating the ice particles as they travel toward the surface of the semiconductor wafer to partially melt the ice particles and reduce the diameters thereof.
Claim 8
Independent Claim
48 words
A method of cleaning a semiconductor wafer comprising: blasting ice particles at a surface of a semiconductor wafer; heating the semiconductor wafer; and heating the ice particles as they travel toward the surface of the semiconductor wafer to partially melt the ice particles and reduce the diameters thereof.
Claim 9
Dependent Claim
33 words
A method as claimed in claim 6 wherein said heating steps comprise blowing warm air over the semiconductor wafer and the ice particles as they travel towards the surface of the semiconductor wafer.
Claim 10
Dependent Claim
18 words
A method as claimed in claim 7 wherein the temperature of the warm air is approximately 5°-80° C.
Claim 11
Dependent Claim
27 words
A method as claimed in claim 6 including heating the semiconductor wafer on one side and blasting the ice particles against the opposite side of the wafer.
Claim 12
Dependent Claim
16 words
A method as claimed in claim 9, including heating the semiconductor wafer with a hot plate.
Claim 13
Dependent Claim
21 words
A method as claimed in claim 9, including heating the semiconductor wafer to a temperature between room temperature and 200° C.
Claim 14
Independent Claim
33 words
A method of gettering a semiconductor wafer comprising blasting frozen particles at a side of a semiconductor wafer, the frozen particles including nuclei of a relatively hard material and a coating of ice.
Claim 15
Independent Claim
33 words
A method of gettering a semiconductor wafer comprising blasting frozen particles at a side of a semiconductor wafer, the frozen particles including nuclei of a relatively hard material and a coating of ice.
Claim 16
Dependent Claim
13 words
A method as claimed in claim 12 wherein the nuclei are silica particles.
Claim 17
Dependent Claim
24 words
A method as claimed in claim 12 wherein the water from which the ice coating is formed is ultrapure water containing carbon dioxide gas.
Claim 18
Dependent Claim
24 words
A method as claimed in claim 14 wherein the specific resistance of the ultrapure water containing carbon dioxide gas is at most 1 megohm-cm.
Claim 19
Dependent Claim
31 words
A method as claimed in claim 12 including blasting the frozen particles at the surface of the semiconductor at an angle of 30°-80° with respect to a surface of the semiconductor.
Claim 20
Dependent Claim
22 words
A method as claimed in claim 12, including blasting the frozen particles at the surface of the semiconductor wafer with a gas.
Claim 21
Dependent Claim
12 words
A method as claimed in claim 17 wherein the gas is nitrogen.
Claim 22
Dependent Claim
42 words
A method as claimed in claim 12 comprising, subsequent to gettering a side of a semiconductor wafer by blasting it with frozen particles, cleaning the same side of the semiconductor wafer by blasting ice particles made from ultrapure water at the side.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-29 | 1995-01-28 | 1995-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-29 | 1999-01-28 | 1999-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-29 | 2003-01-28 | 2003-07-30 | $7700.00 | Window Closed / Lapsed |